Other than skin cancer, prostate cancer is the most common cancer in American men. According to the American Cancer Society, an estimated 220,800 new cases of prostate cancer and 27,540 deaths from prostate cancer will occur in 2015 in the United States alone. About 1 man in 7 will be diagnosed with prostate cancer during his lifetime. Advances in cancer diagnosis and treatment during the last decade have increased treatment options but have not provided curative treatments for patients with metastatic prostate cancer. Additional therapies are needed for these patients.